The invention is directed to the annual harvesting of cultivated copses, preferably in lines, and is related to the invention described in my U.S. Pat. No. 4,787,917, which discloses a method for the production, harvesting and torrefaction of wood originating from copses grown in lines and harvested manually.
The intensive growing of copses from stumps planted in lines provides strong ligneous stems with small lateral branches, which stems are annually able to reach 300 to 400 cm in height and a diameter of 3 or 4 cm at the base.
Harvesting takes place after the leaves have fallen, and it provides 30 to 40 tons of so-called "green" wood per hectare.
In order to achieve the aims proposed in my U.S. Pat. No. 4,787,917 and other similar aims, it is imperative, at the time of harvesting, to reduce the entire ligneous production into cylindrical sections of approximately 2 to 4 cm in length. In fact, this produces a semi-fluid material with a high apparent density and a natural slope of approximately 40.degree., and the mass thereby formed has a uniform permeability to gasses which will have to pass through it at greater or lesser speed during the processing and use operations my above-noted patent.
So-called "ensilage blower" harveter-chopper machines are in existence. These very powerful machines are currently used for harvesting fodder corn; however, they cannot be used for harvesting copses because none has a gathering system adapted to harvesting highly ligneous stems. Moreover, none of these machines is capable of processing the year-old copse substantially only into cylindrical sections. In fact, the product of harvesting contains, in addition to sections of this shape, more or less long pieces of brushwood originating from the cutting of the lateral branches located on the ligneous stems and a high proportion of crushed wood originating from the badly adapted chopping machine part. The material obtained therefore does not possess the required characteristics.
The published French Patent Applications No. 2,414,297 (T. W. Nicholson) and 2,293,870 (Kyosti Pollari) and the Patent U.S. 4,338,985 (F. M. Smith et al.) also disclose machines for removing the trunks and branches of ligneous plants and for transforming them into chips. None of these machines has been designed to provide cylindrical sections of substantially uniform length.